Change email content

To change the content of the default email templates, you can override the getContent function in the emailDelivery object. It allows you to return an object that has the following properties:

body: This is the email's body. This can be HTML or just text as well.
isHtml: If the body is HTML, then this should be true.
subject: This is the subject of the email to send.
toEmail: The email will be sent to this email.

Other information like which email ID to send from is specified in the smtpSettings object.

NodeJS
GoLang
Python

import supertokens from "supertokens-node";
import ThirdParty from "supertokens-node/recipe/thirdparty";
import Session from "supertokens-node/recipe/session";
import EmailVerification from "supertokens-node/recipe/emailverification"
import { SMTPService as EmailVerificationSMTPService } from "supertokens-node/recipe/emailverification/emaildelivery";

supertokens.init({
    appInfo: {
        apiDomain: "...",
        appName: "...",
        websiteDomain: "..."
    },
    recipeList: [
        ThirdParty.init({
        }),

        // if email verification is enabled
        EmailVerification.init({
            emailDelivery: {
                service: new EmailVerificationSMTPService({
                    smtpSettings: { /*...*/ },
                    override: (originalImplementation) => {
                        return {
                            ...originalImplementation,
                            getContent: async function (input) {
                                // email verification content
                                let { emailVerifyLink, user } = input;

                                // you can even call the original implementation and modify that
                                let originalContent = await originalImplementation.getContent(input)
                                originalContent.subject = "My custom subject";
                                return originalContent;
                            }
                        }
                    }
                })
            }
        }),
        Session.init()
    ]
});

import (
    "fmt"

    "github.com/supertokens/supertokens-golang/ingredients/emaildelivery"
    "github.com/supertokens/supertokens-golang/recipe/emailverification"
    "github.com/supertokens/supertokens-golang/recipe/emailverification/evmodels"
    "github.com/supertokens/supertokens-golang/supertokens"
)

func main() {
    supertokens.Init(supertokens.TypeInput{
        RecipeList: []supertokens.Recipe{
            emailverification.Init(evmodels.TypeInput{
                EmailDelivery: &emaildelivery.TypeInput{
                    Service: emailverification.MakeSMTPService(emaildelivery.SMTPServiceConfig{
                        Settings: emaildelivery.SMTPSettings{ /* ... */ },

                        Override: func(originalImplementation emaildelivery.SMTPInterface) emaildelivery.SMTPInterface {
                            originalGetContent := *originalImplementation.GetContent

                            (*originalImplementation.GetContent) = func(input emaildelivery.EmailType, userContext supertokens.UserContext) (emaildelivery.EmailContent, error) {
                                // email verification email content
                                emailVerificationLink := input.EmailVerification.EmailVerifyLink
                                user := input.EmailVerification.User
                                fmt.Println(emailVerificationLink)
                                fmt.Println(user)

                                // you can even call the original implementation and modify that
                                originalContent, err := originalGetContent(input, userContext)
                                if err != nil {
                                    return emaildelivery.EmailContent{}, err
                                }
                                originalContent.Subject = "My custom subject"
                                return originalContent, nil
                            }

                            return originalImplementation
                        },
                    }),
                },
            }),
        },
    })
}

from supertokens_python import init, InputAppInfo
from supertokens_python.ingredients.emaildelivery.types import EmailDeliveryConfig, EmailContent, SMTPSettings
from typing import Dict, Any
from supertokens_python.recipe.emailverification.types import SMTPOverrideInput as EVSMTPOverrideInput, EmailTemplateVars as EVEmailTemplateVars
from supertokens_python.recipe import emailverification

def custom_smtp_email_verification_content_override(original_implementation: EVSMTPOverrideInput) -> EVSMTPOverrideInput:
    original_get_content = original_implementation.get_content

    async def get_content(template_vars: EVEmailTemplateVars, user_context: Dict[str, Any]) -> EmailContent:
        # email verification content
        _ = template_vars.email_verify_link
        __ = template_vars.user

        # you can even call the original implementation and modify that
        original_content = await original_get_content(template_vars, user_context)
        original_content.subject = "My custom subject"
        return original_content

    original_implementation.get_content = get_content
    return original_implementation


init(
    app_info=InputAppInfo(
        api_domain="...", app_name="...", website_domain="..."),
    framework='...',  
    recipe_list=[
        # If email verification is enabled
        emailverification.init(
            mode="OPTIONAL",
            email_delivery=EmailDeliveryConfig(
                service=emailverification.SMTPService(
                    smtp_settings=SMTPSettings(...),  
                    override=custom_smtp_email_verification_content_override
                )
            )
        )
    ]
)